Use of Telehealth Resources in Primary Care and Its Association with Facing the COVID-19 Pandemic in Minas Gerais, Brazil.

Introduction: Use of telehealth (TH) resources increased dramatically during the COVID-19 pandemic. This study set out to examine associations between the level of integration of TH resources and the level of Primary Health Care (PHC) structuring to deal with the COVID-19 pandemic in the State of Minas Gerais, Brazil. Methods: This work was a cross-sectional study conducted through the application of a semistructured questionnaire to a sample of 260 PHC Teams working in the state of Minas Gerais, Brazil, from September to December 2020. This study was approved by the Research Ethics Committee and logged under report number 44.294.637. Results: Two variables were created - Level of the PHC structuring to deal with the COVID-19 pandemic and Level of TH structuring. Variables were grouped into five categories (poor to excellent). Associations between variables were examined using the Tukey's test for multiple comparisons and the Spearman correlation coefficient. Variables associated with socioeconomic dimensions (human development index and Gini index) and health care were also analyzed. Levels of TH structuring in PHC ranged from poor (43%) to regular (40%) in most cases. Most PHC teams had regular (56%) or good (37%) levels of PHC structuring to deal with the pandemic. The greater the availability and use of TH resources at a given unit, the better the structure to face COVID-19 (0.45 - p < 0.001). Conclusion: PHC was structured to tackle the pandemic. However, there is a lot to be done before TH resources are effectively incorporated into PHC. Whenever incorporated, TH resources contributed to a more robust response to the COVID-19 pandemic.

Efficacy of antiseptics and chemomechanical methods for dentin caries lesions: A systematic review with GRADE approach.

Objectives: Selective caries removal aims to remove carious tissue in deep dentin lesions. However, a discussion stands on the value of antiseptics and chemomechanical adjuvant methods to reduce the bacterial load on residual caries lesions. This systematic review has addressed two main clinical questions to compare the antimicrobial efficacy of available methods using (1) antiseptic or (2) chemomechanical agents before restoring dentin carious lesions. Methods: We included randomized and non-randomized controlled trials (RCTs/ NRCTs). We searched eight databases from inception to October 2021. Paired reviewers independently screened studies, extracted data, and assessed the risk of bias. The primary outcome was the reduction in the number of total bacterial in dentin, whereas secondary outcomes were reduction in the number of Lactobacillus and Streptococcus. We used the ratio of ratio of post-treatment to baseline means between two interventions in the logarithmic scale as a proper effect measure. Certainty of evidence was assessed with the Grading of Recommendations, Assessment, Development and Evaluation approach. Results: We included 14 RCTs and 9 NRCTs, with nine interventions. Regardless the method, the number of bacteria at baseline was similar or exceeded that after the intervention, particularly in NRCTs. The evidence was inconclusive for most comparisons. Among antiseptic agents, chlorhexidine (CHX) resulted in an average of 1.14 times [95% confidence interval (CI): 1.08-1.21] more total bacterial than photodynamic therapy in RCTs. Among NRCTS, the natural agents resulted in five times more total bacterial than CHX (95% CI: 2-11). For chemomechanical methods, the control resulted in eight times (95% CI: 4-17) more total bacterial than Carisolv (SHAA). Conclusions: The certainty of the evidence was very low for all comparisons showing uncertainty whether one treatment could be more effective than another for dentin disinfection. So far, exclusively removing soft carious dentin would be enough to reduce the bacterial count.

Adjunctive therapies for in vitro carious lesions: Antimicrobial activity, activation of dentin metalloproteinases and effects on dental pulp cells.

BACKGROUND: Adjunctive therapies used before dental restorative procedures may encourage carious tissue removal. Beyond promising antimicrobial properties, treatments could positively modulate the dentin-pulp complex while not interfering with restoration survival. Herein, we evaluated a set of substances and their effects on carious lesions and the underlying dentin or pulp cells. METHODS: Artificial caries lesions were developed in bovine teeth cavities immersed in Streptococcus mutans and Lactobacillus casei co-cultures. The cavities were treated according to the following groups: Phosphate Buffer Saline (PBS), Chlorhexidine (CHX), Papacárie® (Papain gel), Ozone (O3), and antimicrobial Photodynamic Therapy (aPDT). After treatments, samples were cultivated to count isolated microbial colonies. The zymography assay evaluated the activity of dentin metalloproteinases (MMP-2 and MMP-9). Cell viability was indirectly assessed on human dental pulp cells after 24, 72, or 120 h, whereas the odontodifferentiation potential was evaluated after ten days of cell culture. RESULTS: CHX and aPDT led to around 1 log bacterial load reduction. PBS, CHX, and aPDT showed the eventual expression of MMP-2 and MMP-9. Cell viability was reduced (< 30%) after 120 h for all groups compared to the control. CHX, O3, and aPDT induced greater odontodifferentiation (≈ 20% higher) than PBS and papain gel. CONCLUSION: Adjunctive therapies presented little or no biological significance in reducing bacterial load in artificial carious lesions. Although the activation of endogenous metalloproteinases may represent a possible concern for adhesive restorations, some of these treatments may have a positive role in dental pulp tissue repair.

Comparison of instrumental methods for color change assessment of Giomer resins.

Objectives: The aim of this study was to compare the color change of the Giomer resin composite (Beautifil-Bulk) by using photographs obtained with a smartphone (iPhone 6S) associated with Adobe Photoshop software (digital method), with the spectrophotometric method (Vita Easyshade) after immersion in different pigment solutions. Materials and Methods: Twenty resin composite samples with a diameter of 15.0 mm and thickness of 1.0 mm were confectioned in A2 color (n = 5). Photographs and initial color readings were performed with a smartphone and spectrophotometer, respectively. Then, samples were randomly divided and subjected to cycles of immersion in distilled water (control), açai, Coke, and tomato sauce, 3 times a day, 20 minutes for 7 days. Later, new photographs and color readings were taken. Results: The analysis (2-way analysis of variance, Holm-Sidak, p < 0.05) demonstrated no statistical difference (p < 0.005) between the methods in all groups. Similar color changes were observed for all pigment solutions when using the spectrophotometric method. For the digital method, all color changes were clinically unacceptable, with distilled water and tomato sauce similar to each other and with statistical differences (p < 0.005) for Coke and açai. Conclusions: Only the tomato sauce produced a color change above the acceptability threshold using both methods of color assessment. The spectrophotometric and digital methods produce different patterns of color change. According to our results, the spectrophotometric method is more recommended in color change assessment.

Resistência de união de primers/silanos em superfície de cêramica vítrea / Novel silane/primers bond strength in glass ceramics surface

Objetivo: investigar a resistência de união por cisalhamento de diferentes soluções contendo silano e primer na superfície de Dissilicato de Lítio (IPS e.maxCAD, Ivoclar-Vivadent). Metodologia: 78 blocos cerâmicos foram incluídos em resina acrílica, polidos e lavados em ultra-som por 10 minutos. Os espécimes foram divididos em dois grupos de acordo com tratamento de superfície: Superfície Polida (PS); Ácido Hidro-Fluorídrico 9,5% - 20s (HF). Cada grupo foi dividido em três subgrupos (n = 13), de acordo com o tipo de silano: silano tradicional (Porcelain Prime, Inc. Bisco); mistura de silano e resina (KerrSilane, Kerr); mistura de silano e adesivo universal (Single-bond Universal, 3M Espe). Os espécimes foram montados em um dispositivo padrão para teste de cisalhamento (UltradentBonding Assembly), cimentados com cimento resinoso dual (Duolink Universal™, Bisco Inc.) e foto-polimerizados por 20s. As amostras foram testadas após 24 horas e 90 dias de armazenamento em água destilada a 47°C. Os dados foram analisados por 2-Way Anova e Teste de Tukey (α=5%). Resultados: em geral, os valores de resistência adesiva do silano tradicional foram, estatisticamente, mais elevados do que os outros tipos de silanos. O armazenamento afetou, significativamente, a força de adesão para a maioria dos grupos (p <0,001). O grupo PS apresentou menores valores de resistência adesiva, independentemente da variável (silano vs armazenamento). Conclusões: adequada resistência adesiva pode ser obtida com silanos tradicionais após o pré-tratamento de superfície com ácido HF

Objective: To investigate the efficacy of "new silanes / primer" in the Lithium Disilicate surface (IPS e.maxCAD, IvoclarVivadent-) by means of adhesive shear bond strength test. Methodology: A total of 78 ceramic blocks were embedded in acrylic resin, polished and washed in ultrasound for 10 minutes. The specimens were divided into two groups according to surface treatment: Polished Surface (PS); Hydrofluoric acid 9,5% - 20s (HF). Each group was divided into three sub-groups (n = 13) according to the type of silane used: traditional silane (Porcelain Prime Bisco, Inc.); mixture of silane and resin (Kerr Silane, Kerr); mixture of silane and universal adhesive (Single-bond Universal, 3M Espe). The specimens were mounted on a standard device for shear test (Ultradent Bonding Assembly), cemented with dual resin cement (Duolink Universal ™, Bisco Inc.) and photo-polymerised for 20s. The samples were tested after 24 hours and 90 days of storage in distilled water at 47°C. Data were analyzed by 2-way ANOVA and Tukey Test (α = 5%). Results: In general, the adhesive strength value of traditional silanewas significantly higher than other types of silanes. The storage significantly affects the bond strength (bond) for most groups (p <0.001). The PS group showed lower bond strength values, independent of the variable (silane vs. storage). Conclusions: Suitable adhesive strength can be obtained with traditional silanes, combined with the pre-treatment surface with HF acid.

Avaliação da alteração de cor de uma resina composta "beautiful bulk" submetida à imersão em soluções pigmentantes / Color change evaluation of a composite resin "beautiful bulk" submitted to immersion in pigmentant solutions

Objetivo:O objetivo do estudo foi verificar, in vitro, a alteração de cor da resina composta Beautiful-Bulk®, exposta aos líquidos pigmentantes. Métodos:Foram confeccionados 60 espécimes da resina (15,0 mm de diâmetro e 1,0 mm de espessura, n = 5) nas cores A2, B2 e C2. Os espécimes foram mantidos em uma sala escura por sete dias, em ambiente seco, a 37 °C e, em seguida, foram fotografados com aparelho celular iPhone 6S®. Os espécimes foram divididos aleatoriamente e submetidos a ciclos de imersão em quatro líquidos: água destilada (controle), suco de açaí, Coca-Cola® e molho de tomate. As imersões foram realizadas em sete e quatorze dias de forma cíclica, após a confecção dos espécimes, três vezes ao dia, durante 20 minutos. Ao fim de cada ciclo, novas fotografias foram realizadas. As imagens foram analisadas no programa Adobe Photoshop® e os dados convertidos em L*a*b através de um histograma. A variação de cor (∆E) foi analisada pela escala CIE-Lab. Resultados:A análise dos resultados (One-way ANOVA, Teste de Tukey, p < 0,05) demonstrou que o grupo controle produziu maior alteração de cor (p < 0,05) em sete e quatorze dias na cor A2. A cor B2, no ciclo de quatorze dias, apresentou maior alteração de cor (p < 0,05) para os espécimes imersos em molho de tomate sem diferença estatística (p > 0,05) do controle. Para a cor C2, os espécimes imersos em molho de tomate tiveram maior alteração de cor (p < 0,05) em sete dias. Conclusão:Conclui-se que todas as substâncias pigmentantes e a água destilada foram capazes de produzir grandes alterações de cor na resina Beautifil Bulk®. Existe uma interação significativa entre a cor da resina e agentes pigmentantes.

Aim: This study sought to verify, in vitro, the color change of the nanoparticle composite resin, Beautiful Bulk®, exposed directly to pigmented liquids. Methods: Sixty test specimens were made in a Metal matrix (15.0 mm X 1.0 mm) using composite resin (n = 5) in colors A2, B2, and C2. The specimens were photographed with a smartphone (iPhone 6S®) seven days after the preparation. The specimens were kept in the dark for seven days, dry, at 37°C. The specimens were then randomly divided and immersed in four liquids: distilled water (control), açaí juice, Coca-Cola®, and tomato sauce. The immersions were performed in seven and fourteen days cyclically, three times a day, for 20 minutes. At the end of each immersion cycle, new photographs were taken with the same smartphone. The images were analyzed in the Adobe Photoshop® program, and the data was converted to L* a* b* through a histogram. The color variation (∆E) was analyzed by the CIE-Lab scale. Results: Analysis of the results (Tukey's test, p < 0.05) showed that the control group produced a greater color change (p < 0.05) in seven and fourteen days in the A2 shade. The B2 shade, in fourteen days, showed a greater color change (p < 0.05) for the specimens immersed in tomato sauce with no statistical difference (p > 0.05) of the control. For the C2 shade, the specimens immersed in tomato sauce presented a greater color change (p < 0.05) at seven days. Conclusion: It could therefore be concluded that there is a significant interaction between the composite resin and pigment agents. All pigmented substances produced color changes in the composite resin.

Análise dimensional de moldes de alginato após armazenagem / Dimensional analysis of alginate molds after storage

Objetivo: O objetivo neste trabalho foi avaliar a estabilidade dimensional de moldes de dois diferentes alginatos (Cavex Color Change®, Cavex Holland BV, Netherlands; Hydrogum®5, Zhermack, Italy), armazenados em diferentes intervalos de tempo, utilizando dois dispositivos diferentes (D1 e D2 - figuras 1 e 2 respectivamente). Métodos: Após a manipulação e presa completa dos alginatos, foram realizadas medidas diretamente nos moldes dos alginatos, nos tempos T0, T1, T2, T3, T4 e T5 (imediatamente, 30 minutos, 2 horas, 24 horas, 48 horas e 120 horas, respectivamente), para cálculo do percentual de alteração dimensional dos moldes em cada dispositivo. Os dados foram analisados pelo testes Two-Way ANOVA e Tukey, com nível de significância de 5%. Resultados: A análise estatística mostrou diferença entre os tempos (F=29,956; p<0,001), mas não houve diferença entre os alginatos (F=3,155; p=0,076) para o dispositivo 1. Em relação ao dispositivo 2, houve diferença tanto em relação aos tempos (F=21,495; p<0,001) quanto em relação aos alginatos (F=5,595; p=0,015). Conclusões: Os alginatos testados podem ser armazenados com segurança somente por até duas horas após sua presa.(AU)

LED and Halogen Light Transmission through a CAD/CAM Lithium Disilicate Glass-Ceramic

The effect of thickness, shade and translucency of CAD/CAM lithium disilicate glass-ceramic on light transmission of light-emitting diode (LED) and quartz-tungsten-halogen units (QTH) were evaluated. Ceramic IPS e.max CAD shades A1, A2, A3, A3.5, high (HT) and low (LT) translucency were cut (1, 2, 3, 4 and 5 mm). Light sources emission spectra were determined. Light intensity incident and transmitted through each ceramic sample was measured to determine light transmission percentage (TP). Statistical analysis used a linear regression model. There was significant interaction between light source and ceramic translucency (p=0.008) and strong negative correlation (R=-0.845, p<0.001) between ceramic thickness and TP. Increasing one unit in thickness led to 3.17 reduction in TP. There was no significant difference in TP (p=0.124) between shades A1 (ß1=0) and A2 (ß1=-0.45) but significant reduction occurred for A3 (ß1=-0.83) and A3.5 (ß1=-2.18). The interaction QTH/HT provided higher TP (ß1=0) than LED/HT (ß1=-2.92), QTH/LT (ß1=-3.75) and LED/LT (ß1=-5.58). Light transmission was more effective using halogen source and high-translucency ceramics, decreased as the ceramic thickness increased and was higher for the lighter shades, A1 and A2. From the regression model (R2=0.85), an equation was obtained to estimate TP value using each variable ß1 found. A maximum TP of 25% for QTH and 20% for LED was found, suggesting that ceramic light attenuation could compromise light cured and dual cure resin cements polymerization.

Resumo Avaliou-se o efeito da espessura, cor e translucidez de uma cerâmica vítrea a base de dissilicato de lítio para CAD / CAM sobre a transmissão da luz de unidades de diodos emissores de luz (LED) e de quartzo-tungstênio-halogênio (QTH). Cerâmica IPS e.max CAD nas cores A1, A2, A3, A3.5 de translucidez alta (HT) e baixa (LT) foram cortadas (1, 2, 3, 4, 5 mm). Os espectros de emissão das fontes de luz foram determinados. A intensidade da luz incidente e transmitida através de cada espécime de cerâmica foi medida para determinar a percentagem de transmissão de luz (TP). Um modelo de regressão linear foi utilizado para a análise estatística. Houve interação significativa entre a fonte de luz e translucidez cerâmica (p = 0.008) e forte correlação negativa (r = -0.845, p <0.001) entre a espessura da cerâmica e TP. O aumento da espessura em uma unidade levou a uma redução média de 3.17 em TP. Não houve diferença significativa em TP (p = 0.124) entre as cores A1 (ß1 = 0) e A2 (ß1 = -0.45), mas ocorreu redução significativa para as cores A3 (ß1 = -0.83) e A3.5 (ß1 = -2.18). A interação QTH/HT proporcionou maior TP (ß1 = 0) do que LED/HT (ß1 = -2.92), QTH/LT (ß1 = -3.75) e LED/LT (ß1 = -5.58). A transmissão de luz foi mais eficaz utilizando QTH e cerâmica de alta translucidez, diminuiu à medida que a espessura de cerâmica aumentou, e foi maior para as cores A1 e A2. A partir do modelo de regressão (R2 = 0.85), obteve-se uma equação para estimar o valor de TP utilizando os valores de ß1 encontrado. Foi observada TP máxima de 25% para QTH e 20% para LED, sugerindo que a atenuação promovida pela cerâmica pode comprometer a ativação de um cimento resinoso fotoativado e de ativação dupla.

LED and Halogen Light Transmission through a CAD/CAM Lithium Disilicate Glass-Ceramic.

The effect of thickness, shade and translucency of CAD/CAM lithium disilicate glass-ceramic on light transmission of light-emitting diode (LED) and quartz-tungsten-halogen units (QTH) were evaluated. Ceramic IPS e.max CAD shades A1, A2, A3, A3.5, high (HT) and low (LT) translucency were cut (1, 2, 3, 4 and 5 mm). Light sources emission spectra were determined. Light intensity incident and transmitted through each ceramic sample was measured to determine light transmission percentage (TP). Statistical analysis used a linear regression model. There was significant interaction between light source and ceramic translucency (p=0.008) and strong negative correlation (R=-0.845, p<0.001) between ceramic thickness and TP. Increasing one unit in thickness led to 3.17 reduction in TP. There was no significant difference in TP (p=0.124) between shades A1 (ß1=0) and A2 (ß1=-0.45) but significant reduction occurred for A3 (ß1=-0.83) and A3.5 (ß1=-2.18). The interaction QTH/HT provided higher TP (ß1=0) than LED/HT (ß1=-2.92), QTH/LT (ß1=-3.75) and LED/LT (ß1=-5.58). Light transmission was more effective using halogen source and high-translucency ceramics, decreased as the ceramic thickness increased and was higher for the lighter shades, A1 and A2. From the regression model (R2=0.85), an equation was obtained to estimate TP value using each variable ß1 found. A maximum TP of 25% for QTH and 20% for LED was found, suggesting that ceramic light attenuation could compromise light cured and dual cure resin cements polymerization.

Programa de teleodontologia da UFMG / UFMG teledentistry program

Introdução: O programa de Teleodontologia da Faculdade de Odontologia da UFMG teve início em 2005 com o Projeto BH Telessaúde. Atualmente o programa conta também com outros dois: um desenvolvido na Faculdade de Medicina e o outro no Hospital das Clínicas, ambos da UFMG. Objetivo: Aproximar profissionais dos serviços de saúde e alunos do conhecimento produzido na Universidade resultando em aprimoramento das práticas profissionais e ao mesmo tempo diminuindo o número de encaminhamentos de pacientes para distantes centros especializados e promovendo atualização ou mesmo uma segunda opinião aos profissionais.Descrição da atividade: O programa conta com duas atividades: videoconferências e teleconsultorias. As videoconferências do BH Telessaúde são realizadas mensalmente e tem duração de uma hora e meia. Na Faculdade de Medicina as videoconferências são quinzenais e levam uma hora. Tanto a Faculdade de Medicina quanto o Hospital das Clínicas realizam teleconsultorias on line e off line. Considerações finais: O projeto de extensão apresenta um série de atividades muito relevantes por propiciar uma atualização permanente à distância através de videoconferêcias e teleconsultorias aos profissionais de saúde e aos estudantes da UFMG. Entretanto, o programa tem uma capacidade de alcance bem maior considerando seu ilimitado potencial. A telemática tem uma relevância social inquestionável à medida que encurta distâncias, estimula a integração dos docentes e discentes com o serviço, amplia o conhecimento e melhora o desempenho dos profissionais da saúde (AU).

Introduction: The Teledentistry program of the School of Dentistry at the Federal University of Minas Gerais (UFMG) began in 2005 with the BHTelehealth project. Besides this project, the Teledentistry program works with two others: one developed at the School of Medicine and another at the University Hospital (UFMG). Objectives: Provide professionals of dental health services and students with the knowledge produced in the University, resulting in the updating and improvement of professional practices, and, at the same time, decreasing the need to refer patients to distant specialized centers, and providing professionals with an updated or even second opinion. Description of activity: the program has two telehealth activities: videoconferences and teleconsultations. The BH Telehealth's videoconferences occur once a month and last an hour and a half. The School of Medicine's videoconferences are held fortnightly and last one hour. Both the School of Medicine and the University Hospital hold online and offline teleconsultations. Final considerations: This extension project has a relevant set of activities, insofar as it provides ongoing distance learning through videoconferences and teleconsultations to public health professionals and UFMG students. However, the program has been used at too low a rate, considering its unlimited potential. Telematics has unquestionable social relevance since it shortens distances, encourages professor and student integration with public service, extends knowledge and improves health professional performance (AU).

Light transmission through a translucent fiber post.

This study is a quantitative assessment of the luminous energy transmitted through different translucent fiber posts. After embedding the posts in black resin, the blocks were submitted to sequential cuts in a precision machine, and depths of 16 mm, 12 mm, 8 mm, and 4 mm were assessed for light transmission with a digital photometer. The quantitative analysis showed significant differences between different posts and depths. Furthermore, the values obtained revealed that the quantity of luminous energy transmitted depends on the type of post and that for all of them there was a significant reduction of the quantity of light transmitted as the depth increased. Even without the post, the luminous intensity inside the canal seems to decrease to levels that are insufficient for polymerization, especially in the apical third.

Análise térmica de uma resina composta de nanopartículas: caracterização e envelhecimento / Thermal analysis of nanofilled composite resin: characterization and aging

O objetivo deste estudo foi acompanhar o envelhecimento de uma resina composta de nanopartículas (Concept Advanced®) ao longo de um ano. A caracterização e a avaliação de sua homogeneidade foram realizadas após o envase em seringa de apresentação comercial por meio de Termogravimetria (TG/DTG), Calorimetria Exploratória Diferencial (DSC) e Análise Termomecânica (TMA). No grupo 1, foram realizadas 15 análises ao longo de seringas que não foram submetidas à pressão do êmbolo. Nos grupos 2 e 3, a resina composta foi totalmente removida pela torção do êmbolo e subdividida em cinco porções. Contudo, ao longo do tempo, no grupo 2, as seringas foram mantidas na vertical e no grupo 3, na horizontal. No grupo 4, cada amostra foi obtida de 24 em 24 horas da área central de cada porção por cinco dias. A análise dos diferentes grupos foi realizada em três seringas para os tempos: inicial, seis meses e um ano. As curvas TG/DTG foram obtidas em amostras não polimerizadas, seguindo programa de aquecimento de 25 a 650ºC, em atmosfera dinâmica de ar. A DSC e a TMA foram realizadas apenas no grupo 1, no tempo inicial, para caracterização do material em amostras fotoativadas de 3mm de diâmetro x 1mm de espessura por 20 segundos. As curvas DSC foram obtidas seguindo o programa de aquecimento da temperatura ambiente a 250°C, sob fluxo de nitrogênio. A TMA foi realizada em atmosfera de nitrogênio da temperatura ambiente a 150oC. As curvas TG/DTG de cada área analisada mostraram o mesmo padrão de decomposição em três etapas com percentuais de perda de massa semelhantes entre todas as amostras independente do tempo de armazenamento. Também o resíduo final, considerado como percentual de carga inorgânica, ficou em torno de 71,5% mostrando homogeneidade de distribuição ao longo das seringas. A pressão contínua determinou alteração estatisticamente significante na estabilidade térmica (p<0,05). Na DSC, as curvas mostraram temperatura de transição vítrea na faixa de 94 a 105ºC e um evento exotérmico a ~160ºC relacionado à polimerização secundária da resina composta. A TMA mostrou três faixas de alterações dimensionais e os valores do coeficiente de expansão térmica linear variaram dentro da mesma seringa, não mostrando homogeneidade de resultados.

The aim of this study was to evaluate the aging of a nanofilled composite resin (Concept Advanced®) during one year. The characterization and evaluation of its homogeneity in commercial syringe was made by Thermogravimetric Analysis (TG/DTG), Differential Scanning Calorimetry (DSC) and Thermomechanical Analysis (TMA). In group 1, 15 analyses throughout syringes were carried without pressing the pestle screw. In groups 2 and 3, the composite resin was all pressed out by the pestle screw and divided in five portions. However, in group 2, throughout the time, the syringes had been kept in the vertical position and group 3 in the horizontal position. In group 4, each sample was obtained every 24 in 24 hours from the central area of each portion during five days. All the analyses of groups 1, 2, 3 and 4 were carried through three syringes in the following times: initial, 6 months and one year. The TG/DTG analyses were carried in not polymerized samples, following a thermal program from 25 to 650ºC, under dynamic air atmosphere. The DSC and the TMA were just carried in group 1, in the initial time, to characterize the material in polymerized samples of 3mm diameter x 1mm thickness per 20 seconds. The curves DSC were obtained following the thermal program from room temperature to 250°C under a nitrogen flow. The TMA was carried under a nitrogen atmosphere from room temperature to 150°C. The curves of TG/DTG showed similar patterns of decomposition in three stages, in all groups independent of the storage time, with similar percentages of loss of mass. Also the weight fraction of inorganic fillers was around 71.5%, showing homogeneity of distribution throughout the syringes. The continuous pressure determined significant alteration in the thermal stability (p< 0,05). The DSC curves showed a glass transition ranged between 94 and 105ºC and eventually an exotherm event at ~160ºC. The TMA showed that the values of the linear coefficient of thermal expansion had varied inside of the same syringe

Análise por imagens dos contatos oclusais em boca e em verticulador / Image analysis of occlusal contacts in the mouth and verticulator

A ocorrência de discrepância qualitativa dos pontos de contato da superfície oclusal dos dentes 24 ao27 foi pesquisada em dois indivíduos, comparando-se imagens digitalizadas obtidas “in vivo” e em modelosmontados em verticulador. Seis modelos parciais, obtidos por meio de moldagem de duplo arco, foram montadosem um aparelho verticulador. Um dispositivo para obtenção de fotografia intra-oral com a mesma distânciafocal e mesmo plano foi desenvolvido e confeccionado. Para o registro dos contatos oclusais foi utilizadopapel carbono de espessura de 0,8 mm. As fotografias foram devidamente organizadas, em pranchas, paraposterior comparação e avaliação qualitativa. Com base nas comparações feitas e na metodologia utilizada,concluiu-se que o aparelho mecânico usado reproduziu os contatos oclusais em boca, sem alteração deposição. A metodologia de digitalização de imagens possibilitou a comparação qualitativa dos contatos obtidosem boca e no aparelho mecânico. Entretanto, é necessário desenvolver-se mais a técnica de obtenção dasfotografias intra-orais para se poder realizar a análise quantitativa.

Análisis de la eficacia de agentes químicos de desinfección en materiales elastoméricos / Analysis of the efficacy of disinfective chemical agents on elastomeric materials

El objetivo de este estudio fue evaluar la eficacia de agentes de desinfección indicados para polisulfuros (mercaptanos), poliéteres y siliconas por condensación y por adición. Fueron confeccionadas noventa muestras de cada material, siendo treinta de ellas contaminadas con Streptococcus mutans o Staphylococcus aureus o Candida albicans. De cada solución microbiana fueron retiradas diez muestras del polisulfeto y de ambas las siliconas, que fueron inmersas por diez minutos en glutaraldehído al 2 por ciento y otras diez inmersas en agua destilada estéril (control negativo). Después de un nuevo lavado en agua destilada, las muestras fueron transferidas a medios de cultivo estériles. Las diez muestras restantes no fueron sometidas al agente de desinfección y fueron transferidas a medios asociados a agentes antimicrobianos específicos (control positivo). La turbidez de los medios de cultivo fue evaluada como indicativo del crecimiento microbiano siguiéndose a la incubación por 24 h a 37O C y se realizó la dilución y sembrado en placas de Petri para contar las colonias. Para el poliéter fue ejecutado el mismo procedimiento, pero el agente de desinfección usado fue el hipoclorito de sodio a 1. No hubo turbidez comprobatoria del crecimiento microbiano en ninguno de los medios de cultivo que contenían los especimenes sometidos a los agentes de desinfección. Se concluyó que el glutaraldehído al 2 por ciento es un agente de desinfección eficaz para el polisulfuro y para las siliconas por adición y por condensación, así como el hipoclorito a 1 por ciento es eficaz para el poliéter, para los microorganismos evaluados

The aim of this in vitro study was to evaluate the disinfection efficacy of elastomeric impression materials such as polysulfides, polyethers, condensation and addition silicones. Ninety samples of each material were made and every thirty samples contaminated with Streptococcus mutans or Staphylococcus aureus or Candida albicans. From each microbial solution there were taken ten samples of polysulfide and of both silicones which were immersed for ten minutes in a 2% glutaraldehyde solution and other ten immersed in sterile distilled water (negative control). After being washed again in distilled water, the samples were transferred to sterile culture medium. The last ten samples were not submitted to any disinfection agent and were transferred to mediums associated with specific anti-microbial agents (positive control). The turbidity of the culture mediums was evaluated as an indication of the microbial growth after a period of 24-hour incubation at 37oC and the dilution and seeding in Petri dishes were done to count the colonies. The same procedure was done for the polyether, but the disinfection agent used was 1% sodium hypoclorite. There was no proved turbidity of the microbial growth in any of the culture mediums which had samples submitted to the disinfection agents tested. It was concluded that the 2% glutaraldehyde is an effective disinfection agent to polysulfides and to both condensation and addition silicones, as well as 1% sodium hypoclorite is effective to polyether, for the tested microorganisms.

O objetivo deste estudo in vitro foi avaliar a eficácia de agentes de desinfecção indicados para polissulfetos, poliéteres e siliconas de condensação e adição. Foram confeccionadas noventa amostras de cada material, sendo cada trinta contaminadas com Streptococcus mutans, Staphylococcus aureus ou Candida albicans. De cada solução microbiana foram retiradas dez amostras do polissulfeto e de ambas as siliconas, que foram imersas por dez minutos no glutaraldeído a 2% e outras dez imersas em água destilada estéril (controle negativo). Após nova lavagem em água destilada, as amostras foram transferidas para meios de cultura estéreis. As dez amostras restantes não foram submetidas ao agente de desinfecção e foram transferidas para meios associados a agentes antimicrobianos específicos (controle positivo). A turbidez dos meios de cultura foi avaliada como indicativo de crescimento microbiano após incubação por 24 h a 37O C e realizou-se a diluição e semeadura nas placas de Petri para contagem de colônias. Para o poliéter foi executado o mesmo procedimento, porém o agente de desinfecção empregado foi o hipoclorito de sódio a 1%. Não houve turvação comprobatória de crescimento bacteriano em nenhum dos meios da cultura que continham corpos de prova submetidos aos agentes de desinfecção. Concluiu-se que o glutaraldeído a 2% é um agente de desinfecção eficaz para o polissulfeto e para as siliconas por adição e por condensação, assim como o hipoclorito a 1% é eficaz para o poliéter, para os microorganismos testados.